Execute the code of the specified module and return the resulting module globals
dictionary. The module’s code is first located using the standard import
mechanism (refer to PEP 302 for details) and then executed in a fresh module
namespace.
The optional dictionary argument init_globals may be used to pre-populate the
globals dictionary before the code is executed. The supplied dictionary will not
be modified. If any of the special global variables below are defined in the
supplied dictionary, those definitions are overridden by the run_module
function.
The special global variables __name__, __file__, __loader__ and
__builtins__ are set in the globals dictionary before the module code is
executed.
__name__ is set to run_name if this optional argument is supplied, and the
mod_name argument otherwise.
__loader__ is set to the PEP 302 module loader used to retrieve the code for
the module (This loader may be a wrapper around the standard import mechanism).
__file__ is set to the name provided by the module loader. If the loader
does not make filename information available, this variable is set to None.
__builtins__ is automatically initialised with a reference to the top level
namespace of the __builtin__ module.
If the argument alter_sys is supplied and evaluates to True, then
sys.argv[0] is updated with the value of __file__ and
sys.modules[__name__] is updated with a temporary module object for the
module being executed. Both sys.argv[0] and sys.modules[__name__]
are restored to their original values before the function returns.
Note that this manipulation of sys is not thread-safe. Other threads may
see the partially initialised module, as well as the altered list of arguments.
It is recommended that the sys module be left alone when invoking this
function from threaded code.